The primary objective of this study is to determine doses of VPA-985 that safely and efficaciously increase serum sodium in patients with hyponatremia from multiple etiologies. The secondary objectives are to determine the effects of VPA-985 on measures of potential clinical benefit in patients with hyponatremia and to compare the effects of VPA-985 in an inpatient setting with those observed during outpatient therapy. Protocol complete. Analysis underway.